1. Field of the Invention
The present invention relates to a head restraint assembly for motor vehicle seats for enabling a head restraint pad to be moved with respect to a motor vehicle seat.
2. Background Art
Motor vehicle seats typically include a head restraint pad mounted to the seat for comfort and safety of the passenger. The head restraint pad is mounted on one or two posts which are inserted into guide sleeves affixed to the seat. The posts typically include retainer notches which allow the head restraint pad to be vertically adjustable.
U.S. Pat. No. 4,854,642 to Hoover Universal, Inc., discloses a head restraint guide assembly having a bushing installed within the seatback for receiving the head restraint pad posts. The head restraint bushing includes extending legs with ramp surfaces so that when the bushing is inserted within the seatback, the legs are resiliently deflected and become locked into place when the installed position is reached. The head restraint post passes through the bushing and has a number of notches which provide detents. A detent lug carried by the bushing engages the detent notches and is resiliently biased against the post. The detent notches are provided with cam surfaces, enabling the head restraint to be raised and lowered to and past the detent positions. The lowermost notch forms a retainer notch with a radial wall which prevents complete removal of the head restraint. A leaf spring actuator can be depressed from outside of the seatback and acts on the detent lug to deflect it out of engagement with the detent notches, thereby enabling withdrawal of the head restraint assembly.
In order to remove the head restraint post, a downward force must be applied to the actuator by a tool such as a screwdriver, causing the lug to move out of engagement with the retainer notch.
U.S. Pat. No. 6,099,077 discloses a head restraint assembly for a motor vehicle. It is commonly owned with the present application and is incorporated herein by reference. That reference discloses actuator springs within a button subassembly that may become over-stressed because their deflection is relatively unconstrained over repeated use. The invention disclosed in U.S. Pat. No. 6,099,077 solves many of these problems.
One difficulty with such conventional approaches is associated with the risk of over-stressing a leaf spring present in a drawer or actuator portion of a head restraint assembly. Accordingly, it would be desirable to limit movement of the leaf of a spring so as to avoid over-stressing it, thereby ensuring that the spring always returns to its undeflected position.
Additionally, it would be desirable to provide a means to satisfy requirements mandated by a regulatory authority or by a customer including a feature which precludes inadvertent removal of the head restraint assembly from the seatback.
According to the present invention, an improved head restraint assembly is provided for enabling a head restraint pad to be lockably positioned with respect to a motor vehicle seatback. The head restraint pad includes at least one post connected to and supporting the head restraint pad. One or more of the posts associated with a restraint pad have at least one retainer notch for vertically adjusting the height of the head restraint pad. The same one post or another of the at least one posts has a square securement notch positioned below the lowermost of the retainer notches. The square securement notch serves to secure the post firmly in relation to the vehicle seatback so that it may not be readily removed therefrom unless a special tool is used.
A tubular bushing is mounted to the seat and has an inside bore sized for receiving the at least one post. The tubular bushing has a head outside the seat and the head has a socket with an open outside end.
A button subassembly is insertable into the open outside end of the socket. The button subassembly locks one of the posts in relation to the tubular bushing and seatback. This assembly has a drawer portion having a leading face and a central portion. The central portion has an aperture through which one of the posts extends. Deployed upon the leading face of the drawer portion is a spring or actuator. The actuator is movable between a forward actuated position in which the actuator is disengaged from any notch in the post and a rearward position to which the actuator is biased. In the forward position, deflection of a leaf of the actuator is limited either by a stop that is also provided by the actuator, or by a constraint imposed by a guide defined upon a rail (not shown). In the rearward position, the actuator engages a notch in the post after the button subassembly is released or snap/slot on guide.
The above objects and other objects, features, and advantages of the present invention are readily apparent from the following detailed description of the best mode for carrying out the invention when taken in connection with the accompanying drawings.